1. Field of the Invention
The field of the invention is to an adapter kit for a catheter introducer, and related method, wherein a catheter is passed into the body in order to transmit a medium either into or from the body through a lumen in the catheter. Of particular interest are heart catheters which are introduced into the heart for monitoring the heart by having its waveforms transmitted from the heart through a lumen in the catheter. The invention will accordingly be described in detail hereinafter by reference to heart catheters wherein the medium transmitted is the waveform for heart monitoring. Furthermore, the waveform distortion hereinafter referred to is the additional waveform distortion caused by the compressive forces used to grip the catheters within the body of the adapter. The waveforms transmitted by the catheters have other inherent distortions caused by resonance, air bubbles, etc. It is not the purpose of this invention to cure those inherent distortions. Additionally, the catheter must be of the type which can be compressed by application of compressive force and must contain a medium for transmitting a waveform which would make that waveform susceptible to compression of the catheter. Rigid catheters that break before deforming under compression or catheters which contain wires for transmitting waveforms are not susceptible to compression of the catheter and therefore will not greatly benefit from this invention.
2. Description of the Related Art
The problems involved in the prior art occur when the catheter contains a lumen for transmitting waveforms for monitoring a heart, which lumen can easily be crushed and/or have any of its transmitted waveforms distorted.
The related prior art has two types of potential problems: Type A problems, Type B problems, and Type C problems.
Type A problems are illustrated by: (1) the Prior Art Tuohy-Borst adapter in FIG. 1 of the Prior Art drawing in the present application; and (2) the related Steigerwald U.S. Pat. No. '346 mentioned first herein.
Type A problems are illustrated by Tuohy-Borst adapter 15 in FIG. 1 for a catheter introducer. It includes adjustable compression cap 17; latex washer 18 forming a seal around catheter 26 to prevent air leaks toward the patient and fluid leaks away from the patient; silicone compression sleeve 19 squeezing around catheter 26 when top cap 17 is tightened to hold catheter 26 in place; hemostasis valve 23 utilizing a duckbill, one-silt design to reduce the potential of air entry and blood loss when catheter 26 is not in place; and nylon washer 20 used to transmit an even force on valve 23, so that valve 23 is positioned correctly in body 21 housing hemostatic valve 23 and compression sleeve 19.
Tuohy-Borst adapter 15 is currently used to secure in place a pulmonary catheter having a lumen, after the catheter has been properly positioned. Problems occur because of the inability of its user to control automatically how much compression cap 17 is tightened, so that the lumen is not crushed or any of its transmitted waveforms distorted.
Adjustable cap 17 is tightened to secure its catheter 26 in place after catheter 26 has been properly axially positioned. However, if compression cap 17 is tightened too much, catheter 26 may become crushed and its transmitted waveforms distorted; but if cap 17 is not tightened enough, catheter 26 will not be properly secured in the position desired against movement relative to adapter 16.
Consider the uncontrolled tightening action: (1) by compression cap 17 on silicone sleeve 19 in adapter 15 in FIG. 1 of the Prior Art drawing in the present application; and (2) on elastic sleeve 112 in U.S. Pat. No. '346 (see lines 33-45, column 7). This uncontrolled tightening is likely to crush any lumen carried by catheter 26, and distort its transmitted waveforms.
Type B problems are illustrated by U.S. Pat. No. 4,000,739 (hereinafter called "U.S. Pat. No. '739"), patented Jan. 4, 1977 by Robert C. Stevens and entitled HEMOSTASIS CANNULA.
In Type B: U.S. Pat. No. '739 operates in a different manner than gland 48 in the present application, since cannula 10, 12 in U.S. Pat. No. '739: (1) relies on the support of gasket 22 to close slit 28 to resist the force exerted by the patient's blood pressure and prevents any blood loss (see lines 40-45, column 3); (2) does not have a mechanism for adjusting the compression, i.e., tightening down around its catheter 46 to immobilize it in place for preventing it from migrating from the desired fixed position; and (3) in its commercially sold form has its cap 12 and body portion 10 welded together, so its disc 22 or 24 cannot be replaced.
Type C problems are illustrated by U.S. Pat. No. 4,177,814 (hereinafter called "U.S. Pat. No. '814"), patented Dec. 11, 1979 by William R. Knepshield and entitled SELF-SEALING CANNULA.
In Type C: U.S. Pat. No. '814 has a trocar, which is a surgical instrument with a rigid metal shaft 18; and is not relevant to the catheter (and to its adapter, art and problems) disclosed in this application. When its rigid metal shaft 18 is removed, air entry and blood loss is prevented by automatically closing sealing slot 30 in valve 26 due to the compressive force (see lines 39-41, column 3). The force required to automatically close its central sealing slot 30 is likely to be sufficient force to crush any lumen carried by any catheter, and to distort its transmitted waveforms.
Adapter 32 of the present invention is an improvement on, and solves and eliminated the aforementioned defects and problems in, the prior art; takes the "guess work" out of the operation; and is designed: (1) to provide maximum resistance to any catheter 34 pull-out force, and (2) not to crush lumen 35 carried by catheter 34, or to distort any catheter monitoring wave forms transmitted by its lumen 35.